I'm new to the forum. This is my first post.
I just got my TF-100 test kit. As you probably know, the test kit comes with a sample of 50ppm CYA water, to help the new tester understand the test.
I followed the directions for the test as printed. Because the provided sample is known to have 50ppm CYA, the dot should be obscured around 50 on the test vial. At this level, the dot is still clearly visible. It doesn't disappear until about the 40 mark on the vial. I followed the directions accurately, twice, with the same results-- the dot's not even close to vanishing at 50, always around 38-40. I've poured the fluid out and repeated the fill many times, with consistent results of 38 (a little higher than the 40 mark). But not the 50 it SHOULD be.
I'm doing the test outside, observing the test tube with my back to the sun, as suggested in the video (though in the video, the tester is facing the sun).
I watched the TF CYA video, and referred to the test pics on Taylors website. I'm not even close.
This is the first test I'll do when I think I have it working, so I don't have any other data, yet.
Any help would be great.